2005 Polaris Sportsman 400/500 Service Manual, Page 131Get this manual
FUEL SYSTEMCARBURETION G Poor fuel quality (old fuel) Loose jets Worn jet needleneedle jet or other carburetor parts Dirty carburetor (air bleed passages or jets) Weak or damaged vacuum piston return spring Fouled spark plug Plugged or restricted idle jet
POOR IDLE Idle Too High Idle adjusted improperlyidle mixture screw damaged Sticky vacuum slide Throttle cable sticking, improperly adjusted, routed incorrectly Choke cable sticking, improperly adjusted, routed incorrectly Plugged or restricted idle jet Idle Too Low Choke cable bending or incorrectly adjusted Idle speed set incorrectly Idle mixture screw misadjusted or damaged Belt dragging Ignition timing incorrect Worn jet needleneedle jet Plugged or restricted idle jet